Boiler



(No Model.) 2 SheetS -Sheet 1'. W. E. DEAN.

BOILER, No. 380,746.- Patented Apr. 10, 1888.

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W. E. DEAN BOILER.

No. 380,746. Patented Apr. 10, 1888.

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NITED STATES PATENT OFFICE.

WILLIAM E. DEAN, OF MINNEAPOLIS, MINNESOTA.

BOILER.

QPECIPICAI'ION forming part of Letters Patent No. 380,746, dated April 10, 1888.

Application filed November 21, 1887. Serial No. 255,698. No model.)

To all whom it may concern:

Be it known that I, WILLIAM E. DEAN, of Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain Improvements in Boilers, of which the following is a specification.

My invention relates to improvements in boilers for generating steam; and it consists, generally,in the construction and arrangement hereinafter described, and particularly pointed out in the claims.

In the drawings which form part of this specification, Figure 1 is a longitudinal section of a portion of my improved boiler. Fig. 2 is a crosssection taken on line 00 a: of Fig. 1. Fig. 3 is a cross-section taken on line y y of Fig. 1. Figs. 4 and 5 are cross-sections showing a modification in the construction.

In the drawings, 2 represents the outer plate of a horizontal boiler of ordinary construction having heads 4, to one of which are preferably secured the fire-boxes 6. These fire boxes may be of any convenient size and number, and are preferably made cylindrical in form and ex- 0 tend into the shell of the boiler, so as to be,

surrounded by the water in the boiler. A combustion chamber, 8, communicates with the front end of the fire-boxes, to which it is attached by a suitable throatsheet properly flanged and calked to make a watertight front between the fire boxes and the combustionchamber. I prefer to construct the combustion-chamber in such a manner that its op posing sides will be parallel to each other, to enable me to introduce water-tubes 12 in alter nate rows, extending in opposite directions from side to side, for the circulation of water through, as well as around, the said combustion-chamber. In using a combustion chamber of this kind made square or rectangular in crosssection the diliiculty has been that, as it is necessary for proper circulation to place the water-tubes diagonally to the water level, the sides of the combustion-chamber must nee essarily be diagonal or at right angles to the tubes passing through them, and in order to keep the upper corner of the combustionchamber below the waterline the size of the square chamber is reduced to such a degree as to give a large amount of dead-water between the side of the combustion-chamber and the shell, so that it has been found necessary to accompany this construction with longitudinal tubes placed around the combustionchamher, in order to sufficiently divide up this wa tor-space and make it effective for steam-generation. To obviate the necessity of thus supplementing the combustion-chamber and to greatly increase the heating-surface, I form the top of the chamber 8 with one or more rightangular breaks or recesses, 10. The opposing walls of these recesses will be parallel to the sides of the chamber, and the tubes 12, passing from the outside of the chamber, will be received by these walls in as efficient a manner as if the sides were extended and the square completed. The wall-surface of the combustion-chamber is substantially the same as it would be if the chamber were a complete rectangle in cross'section.

It will be seen that by this construction I am enabled to make the crosssection of the combustion-chamber sufficiently large to fill the space in the shell and leave only a comparatively small amount of water-space below and around the said chamber, all of which can be utilized for steam-generation by the heat radiated directly from the combustion-chamber, and the increased circulation in the tubes by the expansion and ebullition of the water as it passes through them will keep this water in constant circulation and allow no dead-wa ter to remain at any point in the boiler, the top of the combustion-chamber formed with one or more depressions can be kept below the ordinary water-level, and the requisite amount of steam-space can be maintained. The construction of the cornbustionchamber which I prefer is shown in Figs. 2 and 3, in which two right-angular breaks or recesses, 10, are used. I may in some instances prefer to use one, as shown in Figs. 4 and 5, or in the case of extremely large boilers it may be nec essary to use more than two in order to acco1nplish the required result.

It is an advantage to use as many of the re cesses as possible and properly secure the tubes, for the reason that the length of the tubes, and consequently the heating-surface,

will be somewhat increased and the depth of 100 each recess will be lessened and less water will be carried above the ends of the tubes.

Although by my construction I am enabled to adapt a boiler of this construction to be used with an internal fire-box, I do not confine myself to this construction. I may find it convenient to use my combustion-chamber in an externally-fired boiler.

I claim as my invention 1. Ina boiler, the combination, with the shell, of the horizontal combustion-chamber having its opposing walls parallel to eachother and provided with a right-angular break or breaks formed in the top of said chamber, and the tubes having their ends secured in the opposite parallel walls of the chamber, substantially as described.

2. In a boiler, the combination, with the shell 2, of the horizontal combustion-chamber 8, provided with the recess 10 in its top, having its walls parallel with the bottom walls of the chamber, and the series of tubes extending transversely through the said combustionchamber, with their ends secured in its opposing Walls.

In testimony whereof I have hereunto set my hand this 14th day of November, 1887.

WILLIAM E. DEAN.

In presence of R. H. SANFORD, A. 0. PAU 

